Age trajectories of total and cause-specific mortality, morbidity, and disability as well as those of biomarkers are fundamental data in aging research. Patterns and differentials of these age trajectories reflect the mechanisms of senescence, evolutionary backgrounds of the mechanisms, relationships between senescence and diseases, and environmental and genetic effects on senescence. In order to analyze the age trajectories in more depth than in previous studies and detect clues about the underlying senescent processes, innovative quantitative approaches need to be developed. Thus statistical demographers experienced in age variation analysis have high potentials to make important contributions to biomedical gerontology. The background of the candidate, Shiro Horiuchi, is formal and mathematical demography. This proposal seeks funds for him to develop his career as an independent scientist in the biodemography of aging, by conducting the proposed research, strengthening this biomedical background, and broadening his collaborative network with biomedical investigators. His environment is highly suitable for his career development: the Rockefeller University is known for high quality in biomedical research and cooperates closely in training and research with Cornell University Medical College and Memorial Sloan Kettering Institute; and the Laboratory of Populations at RU pursues quantitative approaches to biomedical problems. (Since his research is statistical data analysis, other sources of research support will not necessarily be needed.) Horiuchi's recent studies have underscored the importance of age variations in the rate of senescence progression. In the proposed research, he will (a) compare patterns of the rate of relative mortality increase with age (life table aging rate, or LAR) among various species; (b) examine if environmental and genetic risk factors (in particular, smoking and high-fat diet) not only raise the overall levels of total and cause-specific mortality but also accelerate their age-related increases; (c) investigate senescence-rooted interdependence among major causes of death by examining interrelationships among LAR patterns of degenerative diseases; (d) analyze aging rate patterns of morbidity, disability, and biomarkers with emphasis on dementia-related variables; and compare differential aging rate profiles by race/sex categories.